title: In Planta Biocontrol of Pectobacterium atrosepticum by Rhodococcus erythropolis Involves Silencing of Pathogen Communication by the Rhodococcal Gamma-Lactone Catabolic Pathway.
abstract: The virulence of numerous Gram-negative bacteria is under the control of a quorum sensing process based on synthesis and perception of N-acyl homoserine lactones. Rhodococcus erythropolis, a Gram-positive bacterium, has recently been proposed as a biocontrol agent for plant protection against soft-rot bacteria, including Pectobacterium. Here, we show that the γ-lactone catabolic pathway of R. erythropolis disrupts Pectobacterium communication and prevents plant soft-rot. We report the first characterization and demonstration of N-acyl homoserine lactone quenching in planta. In particular, we describe the transcription of the R. erythropolis lactonase gene, encoding the key enzyme of this pathway, and the subsequent lactone breakdown. The role of this catabolic pathway in biocontrol activity was confirmed by deletion of the lactonase gene from R. erythropolis and also its heterologous expression in Escherichia coli. The γ-lactone catabolic pathway is induced by pathogen communication rather than by pathogen invasion. This is thus a novel and unusual biocontrol pathway, differing from those previously described as protecting plants from phytopathogens. These findings also suggest the existence of an additional pathway contributing to plant protection.
authors.affiliation: Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312) - Normandie Université - Université de Rouen - IUT Evreux, Evreux, France.
authors.forename: Corinne
authors.initials: C
authors.lastname: Barbey
authors.forename: Alexandre
authors.initials: A
authors.lastname: Crépin
authors.forename: Dorian
authors.initials: D
authors.lastname: Bergeau
authors.forename: Asma
authors.initials: A
authors.lastname: Ouchiha
authors.forename: Lily
authors.initials: L
authors.lastname: Mijouin
authors.forename: Laure
authors.initials: L
authors.lastname: Taupin
authors.forename: Nicole
authors.initials: N
authors.lastname: Orange
authors.forename: Marc
authors.initials: M
authors.lastname: Feuilloley
authors.forename: Alain
authors.initials: A
authors.lastname: Dufour
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Burini
authors.forename: Xavier
authors.initials: X
authors.lastname: Latour
mesh_terms: D054742:Acyl-Butyrolactones / Q000032:analysis / Q000378:metabolism* / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D004926:Escherichia coli / Q000378:metabolism; D013058:Mass Spectrometry; D018613:Microscopy, Confocal; D044043:Pectobacterium / Q000502:physiology*; D035281:Plant Tubers / Q000382:microbiology; D053038:Quorum Sensing / Q000187:drug effects; D012240:Rhodococcus / Q000235:genetics / Q000378:metabolism*; D011198:Solanum tuberosum / Q000382:microbiology
chemical_list: D054742:Acyl-Butyrolactones; D001426:Bacterial Proteins